libwebp_sys

Function WebPEncodeLosslessRGBA

Source 
pub unsafe extern "C" fn WebPEncodeLosslessRGBA(
    rgba: *const u8,
    width: c_int,
    height: c_int,
    stride: c_int,
    output: *mut *mut u8,
) -> usize
Expand description

Equivalent to WebPEncodeRGBA, but compressing in a lossless manner. Files are usually larger than lossy format, but will not suffer any compression loss. Note these functions, like the lossy versions, use the library’s default settings. For lossless this means exact is disabled. RGB values in transparent areas will be modified to improve compression. To avoid this, use WebPEncode() and set WebPConfig::exact to 1.